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JOURNAL OF THE ATOMIC ENERGY SOCIETY OF JAPAN 2001年第8期43卷 830-835页

作者： Katsumata, R Shimazu, Y Hokkaido Univ Grad Sch Engn Dept Quantum Energy Eng Sapporo Hokkaido 060 Japan

Recently, an applicability of wavelet transform for estimation of moderator temperature coefficient was shown in numerical simulations. The basic concept of the wavelet transform is to eliminate noise in the measured signals. The concept is similar to that of Fourier transform method in which the analyzed reactivity component is divided by the analyzed component of relevant parameter. In order to apply the method to analyze measured data in actual PWRs, we carried out numerical simulations on the data that were more similar to actual data and proposed a method for estimation of moderator temperature coefficient using the wavelet transform. In the numerical simulations we obtained moderator temperature coefficients with the relative error of less than 4%. Based on this result we applied this method to analyze measured data in actual PWRs and the results have proved that the method is applicable for estimation of moderator temperature coefficients in the actual PWRs. It is expected that this method can reduce the required data length during the measurement. We expect to expand the applicability of this method to estimate the other reactivity coefficients with the data of short transient.

关键词： moderators temperature coefficient temperature dependence wavelet transform linear fitting method expansion coefficients decomposition level reactivity coefficients

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Effects of DC Stray Current on the Polarization Characteristics of X70 Steel

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INTERNATIONAL JOURNAL OF ELECTROCHEMICAL SCIENCE 2018年第12期13卷 12099-12117页

作者： Wang, Jun Li, Zili Kong, Chuanping Yang, Ziqing Liu, Jianguo Cui, Gan China Univ Petr Coll Pipeline & Civil Engn Prov Key Lab Oil & Gas Storage & Transportat Secu Qingdao 266580 Shandong Peoples R China

To investigate polarization characteristics of X70 steel at direct current densities in the 50 similar to 1200 A/m(2) range under anodic and cathodic interferences, electrochemical method was used to test Tafel polarization curves. The critical current density was 180 A/m(2) and equal or above this value the Tafel polarization curves were linear. By fitting these curves, we obtained polarization resistance R-p, which can be used to characterize the polarization characteristics of X70 steel at DC current. R-p decreased with an increase in the DC current density under both cathodic and anodic interferences. Relational between R-p and DC current density was calculated. As the anodic interference current density increased, corrosion potential of X70 steel shifted positively. Opposite behavior is observed in the case of cathodic interference.

关键词： DC stray current X70 steel corrosion linear fitting method polarization resistance

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Angle-Weighted trilateration method fusing multi-data processing technologies in indoor scene

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DIGITAL SIGNAL PROCESSING 2024年 147卷

作者： Zang, Liguo Jiao, Jing Wang, Jie Ding, Ning Wang, Zizhou Min, Xinyi Nanjing Inst Technol Sch Automobile & Rail Transportat Nanjing 211167 Peoples R China

The trilateration method based on Ultra-Wideband (UWB) technology is widely used in indoor positioning. However, the complexity of indoor environment will affect the transmission of UWB signals, reducing accuracy of trilateration method. Therefore, an Angle -Weighted trilateration method fusing multi -data processing technologies is utilized. By analyzing the relationship between positioning accuracy and inner angles of the error triangle generated by trilateration method, the rule of measuring positioning accuracy with angle as weight is determined. The triangle is corrected by the rule, and the corrected triangle is solved by centroid method to obtain accurate positioning results. In addition, the linear fitting method, Kalman Filter algorithm and Unscented Kalman Filter algorithm are used to process ranging and positioning results of the system, aiming to reduce error range of positioning. In static environment, the Root Mean Square Error of the utilized method is about 10 mm, and the Mean Absolute Error is within 3 mm. In dynamic environment, the Root Mean Square Error of the utilized method is within 40 mm, and the Mean Absolute Error is within 20 mm. The Angle -Weighted trilateration method fusing multi -data processing technologies can improve accuracy and stability of the positioning system.

关键词： Angle -Weighted trilateration Filtering algorithm Indoor positioning linear fitting method UWB

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A Structure Optimized method Based on AFSA for Soft Magnetic Strips of Inner Double-Layer Shield for Wireless Power Transmission of EV

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WORLD ELECTRIC VEHICLE JOURNAL 2022年第3期13卷 49页

作者： Sun, Yening Wei, Yao Tian, Yi Hebei Jiaotong Vocat & Tech Coll Dept Elect & Informat Engn Shijiazhuang 050099 Hebei Peoples R China Chinese Acad Sci Quanzhou Inst Equipment Mfg Haixi Inst Quanzhou 362000 Peoples R China Yanshan Univ Coll Elect Engn Qinhuangdao 066104 Hebei Peoples R China Beijing Jiaotong Univ Sch Elect Engn Beijing 100044 Peoples R China

A structure optimized method based on the artificial fish swarm algorithm (AFSA) for the soft magnetic strips of the inner double-layer shield is proposed in this paper and applied to the coupler of the wireless power transfer (WPT) system of an electrical vehicle (EV). Some structure parameters including length, height, width and distances of the strips are selected to fit their relationships with the coupling coefficient, which directly effects the transfer efficiency of the coupler by the linear fitting method. Based on these relationships, a group of parameters is obtained by the AFSA with the largest coupling coefficient and suitable volume to achieve optimal transfer efficiency without lots of repetitive results of the finite element analysis. The effectiveness of the proposed method is demonstrated quantitatively according to the outcomes and comparisons among different structure parameters and algorithms.

关键词： WPT double-layer shield linear fitting method AFSA

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An Improved Canny Edge Detection Algorithm 8

An Improved Canny Edge Detection Algorithm

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8th IEEE International Conference on Software Engineering and Service Science (ICSESS)

作者： Xuan, Li Hong, Zhang Shenyang Aerosp Univ Sch Elect Informat Engn Shenyang Liaoning Peoples R China

ISBN: (纸本)9781538604977

The traditional Canny algorithm has been applied to image edge detection. However, this traditional algorithm can't adaptively determine the filtering threshold value and it can't separate targets from background, when filtering the lower contrast image. Therefore, in response to these problems, this paper proposed an improved method on Canny algorithm. Two adaptive thresholds were obtained by doing differential operation on amplitude gradient histogram. Then we connected edge points to get some generalized chains. After that, it needed to calculate their mean value to delete generalized chains, which are smaller than the mean value. Finally, the image edge detection results were got by linear fitting method. Experimental results show that the improved algorithm is more robust to noise and it can clearly separate targets from background.

关键词： edge detection Canny algorithm adaptive threshold generalized chains linear fitting method

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Visual prediction of gas diffusion concentration based on regression analysis and BP neural network

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JOURNAL OF ENGINEERING-JOE 2019年第13期2019卷 19-23页

作者： Wang, Jing Fang, Jiandong Zhao, Yvdong Inner Mongolia Univ Technol Hohhot Peoples R China Inner Mongolia Autonomous Reg Agr & Anim Husb Inf Hohhot Peoples R China

In order to realise the prediction of the diffusion trend of chemical gases under toxic, flammable, and explosive conditions, this article used a multiple regression model and a back propagation (BP) neural network model, established two kinds of leakage gas diffusion models based on Fluent simulation data. First, the multivariate function relation between multiple influencing factors and diffusion concentration is established by using linear fitting method, i.e. multivariate regression model. Second, according to the large number and non-linearity of Fluent simulation data of leakage gas, a three-layer BP neural network prediction model for leakage gas, wind speed, X-axis diffusion distance, and Y-axis diffusion distance was established by using BP neural network algorithm. Under the same data conditions, the prediction error of BP neural network prediction model is smaller than that of multivariate reversion model, and the fitting degree is high, but the stability of multiple linear regression is better.

关键词： backpropagation neural nets diffusion regression analysis toxicology chemical engineering computing finite element analysis explosive conditions multiple regression model BP neural network model leakage gas diffusion models Fluent simulation data multivariate function relation multiple influencing factors linear fitting method nonlinearity three-layer BP neural network prediction model diffusion distance BP neural network algorithm data conditions prediction error multivariate reversion model multiple linear regression visual prediction gas diffusion concentration regression analysis diffusion trend chemical gases toxic conditions flammable conditions

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Analysis of factors influencing the parameters of electromagnetic environment

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JOURNAL OF ENGINEERING-JOE 2019年第16期2019卷 2787-2789页

作者： Yu, Zhanqing Wang, Xiaorui Zeng, Rong Fu, Yin Liu, Lei Li, Min Tsinghua Univ Dept Elect Engn Beijing Peoples R China China Southern Power Grid Elect Power Res Inst Guangzhou 510000 Guangdong Peoples R China

Electromagnetic environment (EME) is one of the key issues during the ultra-high voltage direct current power transmission projects. There are many factors affecting the parameters of the EME, which are mainly divided into line structure parameters and meteorological parameters. In this study, the concept of variable selection is used to analyse the influence of different factors on the EME parameters and to determine the factors which have greater influence. By comparing the advantages and disadvantages of the subset selection method and the compression estimation method, the more reliable results are determined. Then physical model and linear fitting method are used to analyse the influential factors of corona loss, audible noise, and radio interference.

关键词： corona electromagnetic compatibility DC power transmission radiofrequency interference linear fitting method electromagnetic environment ultra-high voltage direct current power transmission projects line structure parameters meteorological parameters EME parameters subset selection method compression estimation method physical model variable selection concept corona loss audible noise radio interference

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An Improved Canny Edge Detection Algorithm

An Improved Canny Edge Detection Algorithm

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2017 IEEE 8th International Conference on Software Engineering and Service Science

作者： Li Xuan Zhang Hong School of Electronic Information Engineering Shenyang Aerospace University

The traditional Canny algorithm has been applied to image edge detection. However, this traditional algorithm can’t adaptively determine the filtering threshold value and it can’t separate targets from background, when filtering the lower contrast image. Therefore, in response to these problems, this paper proposed an improved method on Canny algorithm. Two adaptive thresholds were obtained by doing differential operation on amplitude gradient histogram. Then we connected edge points to get some generalized chains. After that, it needed to calculate their mean value to delete generalized chains, which are smaller than the mean value. Finally, the image edge detection results were got by linear fitting method. Experimental results show that the improved algorithm is more robust to noise and it can clearly separate targets from background.

关键词： edge detection Canny algorithm adaptive threshold generalized chains linear fitting method

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